Base64 Encoder & Decoder

Free Online Base64 Encoding and Decoding Tool

The CSV-X Base64 Encoder and Decoder is a free online tool that converts text to Base64-encoded strings and vice versa. Base64 encoding is a binary-to-text encoding scheme that represents binary data in an ASCII string format by translating it into a radix-64 representation. It is widely used in web development, email systems, data URLs, and API authentication to safely transmit binary data over text-based protocols.

Developers commonly encounter Base64 in several contexts: embedding images in HTML and CSS using data URIs, encoding authentication credentials for HTTP Basic Auth headers, encoding binary data for JSON payloads, and working with email attachments in MIME format. This tool makes it easy to quickly encode text for these use cases or decode Base64 strings you encounter in API responses, configuration files, or encoded URLs.

How Base64 Encoding Works

Base64 encoding works by taking every three bytes of input data and converting them into four ASCII characters from a set of 64 characters (A-Z, a-z, 0-9, +, /). The equals sign (=) is used for padding when the input length is not a multiple of three. This tool supports full Unicode text through UTF-8 encoding, meaning you can safely encode and decode text in any language, including characters outside the ASCII range. All processing happens locally in your browser using JavaScript's built-in btoa and atob functions with proper Unicode handling.